Jack for derrick legs



May 11 1926.

J. D. M EWEN JACK FOR DERRICK LEGS Filed Dec. 19, 1924 'wrmas szs'Patented May ll,

JOHN D. IVECE'WEN, 0F PITTSBURGH, PENNSYLVANIA, ASSIGNOR T0 LEE 0. MOORE8;

COMPANY, INC., 0F PITTSBURGH, PENNSYLVANIA, COEPORATIGN 0F PENNSYL-VANHL.

anon non DERRICK Lnes.

Application filed December 19, 1924-. Serial No. 756,955.

This invention .relates to derricks for oil wells and the like. Moreparticularly the invention relates to reinforcing or supplementary legsadapted to be used with a permanent steel derrick tower for the pun poseof strengthening it during the drilling of a well, but intended to beremoved after the well is finished. More particularly still theinvention relates to means for adjusting the length of suchsupplementary or r'einforcing derrick legs.

The objects of the invention are to provide an extensible member orjack, adapted to be positioned in the reinforcing legs of a derrick,whereby the length of the supplementary leg may be adjusted to insurethe carrying of its proper part of the derrick load. The specificobjects and advantages of the invention will appear more fully from aconsideration of the following specification and the drawings.

Referring to the drawings, Fig. 1 is-a side view of the two legs formingthe corner of a well drilling derrick, as when the permanent tower isreinforced with supplementary legs, the adjusting jack of this inventionbeing app-lied to the reinforcing Fig. 2 is an enlarged vertical sechthe jack and the leg sections to which it is plied.

in building steel derricks for oil wells it has been found that theiderrick necessary to support the drilling operation is much strongerthan is required after the well is completed, for maintenance purposes,such as pumping, etc. lln recent years the practice has arisen oferecting a light steel derrick tower, of suficient strength formaintenance purposes, but not strong enough for drilling operations, andthen temporarily reinfo cing the legs of this light derrick byadditional legs attached to the permanent ones, these reinforcing legsbeing used only until drilling is completed. They may then be removed.Should conditions at any later time require stronger derrick, thereinforcing legs may be replaced. as in the first instance.

There has existed in such construction a driving-wedges under the lowerends of the able base or foundation, and it supports in a socket thepermanent tubular leg sections 2,

placed end upon end and clamped together in well known manner. At thetop, castings 3 are positioned on the tubular leg members for attachingto the upper terminal structure of the derrick. Clamps 1 are. attachedto the leg sections 2 and to these clamps by means of tongues 5-5, and6, are attached braces and girts extending to adjacent legs, in wellunderstood manner. The clamps themselves are held on the leg sections bymeans of compression bolts 7.

The supplementary or reinforcing legs to be used forstrengthening thederrick during drilling operations are formed of leg sections 10,preferably tubular in form. The lowermost of these seats over aretaining lug 11 positioned on the upper face of the casting 1, and thereinforcing leg is attached to the permanent leg by means of U-shapedloops 12, extending around the two legs and clamping them together bymeans of terminal cross members 13 and nuts let. Wedge shaped spacers 15are positioned between the tubes, all as clearly shown in Fig. 1. Thisparticular construction is no part-of the present invention.

In order to secure proper adjustment of the reinforcing leg made up ofthe sections 10, T position between any two convenient adjacentsectionsa jack construction, illustrated in detail in Fig. 2.

This comprises a nut 20 having a knurled head, and a concentricextension 21 adapted to fit inside the lower end of one. of the tubularsections 10, the tube end seating upon a shoulder formed between the.head 20 and extension 21, as clearly shown in Fig. 2. The extension 21has a threaded hole tapped therein, for receiving a set screw 22, the

head of which is adapted to be positioned in an opening 23 in the lowerend of the tube When the set screwis in position as shown in Fig. 2 itefiect ally locks the nut in the lower end of that section, keeping itfrom falling out, and also preventing its rotation.

A screw 25 is threaded through a central bore in the nut abovedescribed. The lower end of this screw is tapered, and adapted to havesecured thereon a. knurledhead 30, retained rigidly on the screw bymeans of a locking pin 31. Holes 32 and 33 extend through the head andthe screw 25, as

illustrated. The .outer periphery. of the rick is first erected with thelegs 2, suitably connected by cross braces, etc. Then the re-v inforcingleg is built up by positioning the leg sections 10 at any convenientpoint,

usually near the top of the derrick; clamp 4 is slipped over theuppermost of these leg sections; the jack member is positioned at thetop of the uppermost section; the next sectionlO isthenpositioned on theack, as

shown in Fig. 2 and succeedingleg sections are positioned and clampedtogether in normal manner.

- 10 bears against the lower face of the terinforcing leg tocause it tocarry its part of minal casting 3. In order to extend the re the load,the set screw 22 is positioned, thus locking the nut 20 against rotationin the leg sections10. A pin is then inserted through one of the holes32 or 33, and the head 30 is rotated, driving the screw 25in the nut20,ina direction-to raise the nut. The jack is turned up until theproperressurer-is obtained on the reinforcing eg. Then the driving pinis removed, the clamp 40 is raised until itcovers the two knurled por-The uppermost leg section tions 20 and 30, and it is clamped in p051-tion to grip both of those knurledsurfaces, thus locking them in fixedrelative position.

When the well has been completed and it .is desired to remove thereinforcing legs, the

clamp 40 is loosened and lowered, the head 30 is turned in reversedirection to release the screw presnue, and this permits rea'dyrcmovalof the reinforcing legs.

While I have illustrated and described a tubular derrick, modificationscan be made. I

in the jack adapting it for use with any type of legs built up ofsections.

I claim:

1. The combination with a sectional leg for derricks of a jackscrewhaving a fixed head adapted to engage oneend of the leg section anda rotatable nut adapted to engage the end of an adjacent leg section,and

a clamp adapted to. engage the peripheries 1 of the head and nut to holdthem in sid justed position. I

2. The structure described in claim. 1

. further characterized by the fact that the said head and nut haveknurled peripheries for engagement by the said-clamp. 3

3. The combination with a leg for derricks of a jack screw adapted tovary the length of the said leg, said screw havinga relatively rotatablenut adapted to engage the end of one leg section, means to attach thenut to the leg section, a fixed head on'oneend of the screw, sa'id headbeing adapted to engage. theend of an adjacent leg section and-berotatable in respect thereto, and a clamp adapted to engage the saidhead and nut to prevent relatim rotation thereof.

4.,The combination with al sectionalleg for .derricks of a jack screwhaving a-fixeid head adapted to engage one end of a leg section, and arotatable nut adapted tof engage the end of an adjacent leg section. i

5. The combination witlra tubular sectional leg. for derricks of a jackscrew hav-' ing a fixed head adapted-to fit into and be attachedto oneend of-a legsection, and a rotatable nut-adapted to engage'the-end of anadjacentleg section. I H p In testimony whereof, I'sign my name.-

JOHN n McE'WEN.

